The impact of drying and extraction methods on total lipid, fatty acid profile, and cytotoxicity of Tenebrio molitor larvae

Abstract

The rising cultivation of edible insects at an industrial level highlights the importance of employing appropriate post-harvest methods for processing safe and fine-quality insect-based products. The study investigated the impact of different drying and extraction methods on the quality of Tenebrio molitor larvae powder. Two drying treatments, microwave and oven drying, were evaluated followed by total lipid extraction using various methods. Soxhlet extraction with an n-hexane–EtOH (3:1) mixture was effective, yielding 37.85% (microwave) and 38.85% (oven). The highest fatty acid (FA) content was 9-octadecenoic acid, methyl ester (E)-(C18:1). The Schlechtriem and Bligh and Dyer (BD) methods resulted in higher total lipid yields, with BD yielding 56.66% in oven-dried samples. FA profiles were consistent, with monounsaturated FAs predominant. Oven-dried samples had higher saturated FAs. Phenolic content was greater in oven-dried samples, with the n-hexane–EtOH extraction showing the highest total phenolic content (0.09 ± 0.02 mg GAE/100 mg). BD extract from oven-dried samples was the most cytotoxic, significantly reducing cell survival against A549 cells (IC50 = 458.6 µg/mL) and inducing apoptosis at 250 µg/mL. This study underscores the importance of post-harvest methods in producing high-quality insect-based products, revealing that oven drying and specific solvent extractions can enhance total lipid yield, phenolic content, and cytotoxic effects on cancer cells.

Keywords

• cytotoxicity
• drying methods
• fatty acid
• soxhlet
• yellow mealworm